AI advice suppresses people's willingness to say "I don't know", even when the advice is wrong and accuracy is incentivized
Chiara Marcoccia, Walter Quattrociocchi, Valerio Capraro
Don't assume users will self-regulate around bad AI advice. The metacognitive threshold for "I don't know" collapses when AI is present, regardless of accuracy incentives. If answer quality matters more than answer rate, gate AI access or force explicit confidence calibration.
AI assistants answer every question fluently, but human judgment requires knowing when to withhold an answer. Does AI access erode people's willingness to say "I don't know"?
Method: Across five experiments with 3,132 participants, merely having access to AI—even when its advice was engineered to be wrong—nearly eliminated participants' willingness to suspend judgment. They answered more questions but were correct about a third as often as without AI, yet their confidence nearly doubled. Incentivizing accuracy reduced AI reliance and increased suspended judgments, but still far less than when AI was unavailable.
Caveats: Tested on difficult trivia questions. Professional decision contexts with higher stakes may show different patterns.
Reflections: Does the suppression of "I don't know" persist after extended exposure, or do users recalibrate over time? · Can interface design restore suspended judgment without removing AI access entirely? · Do domain experts show the same metacognitive collapse, or does expertise provide resistance?